The present invention relates generally to the field of instrumentation and systems for the spine, and more particularly to instrumentation and systems for use in engaging plates to the spine.
Bony structures are subject to defects and trauma which require a plate to be secured thereto in order to stabilize the bony segment as it heals or fuses. For example, the spine is subject to various pathologies that compromise its load bearing and support capabilities. Such pathologies of the spine include, for example, degenerative diseases, the effects of tumors and, of course, fractures and dislocations attributable to physical trauma. Spinal surgeons have addressed these problems using a wide variety of instrumentation in a broad range of surgical techniques. The use of elongated rigid plates has been helpful in the stabilization and fixation of the lower spine, most particularly in the thoracic and lumbar spine. These same plating techniques have found some level of acceptance by surgeons specializing in the treatment of the cervical spine.
Many spinal plating systems have been developed in the last couple of decades to address some of the needs and requirements for spinal and other bony segment fixation systems. However, even with the more refined plating system designs, there still remains a need for a system that effectively addresses the requirements for such a system. For example, there remains a need for systems and methods for inserting bone engaging fasteners which allow compression and extension of the bony segment to which the plate is attached after the fasteners are inserted. The present invention is directed to satisfying these needs, among others.
The present invention provides a drill guide for forming holes through a plate in a vertebra into which bone engaging fasteners are inserted to engage the plate to the vertebra. The drill guide positions the bone engaging fastener away from the ends of a slotted hole through plate.
The present invention also provides a bone fixation system that includes a plate and a drill guide. The plate includes at least one slotted hole extending therethrough. The drill guide is positionable on the plate such that a hole drilled through the drill guide spaces the screw from the ends of the slotted hole.
The present invention further provides methods for securing a plate to upper and lower vertebrae of a spinal column segment. The plate is fixed to one of the vertebra. A bone engaging fastener engaged to the other vertebra is positioned away from the ends of a slot extending through the plate. The fastener can thus accommodate extension and post-operative settling of the spinal column segment surgeon selectively applies either a compression or distraction load to the spinal column segment with the plate secured to the spinal column segment by the bone engaging fastener.
These and other forms, embodiments, aspects, features, objects of the present invention will be apparent from the following description.